The is_fundamental template of C++ STL is used to check whether the type is a fundamental type or not. It returns a boolean value showing the same.
Syntax:
template <class T> struct is_fundamental;
Parameter: This template accepts a single parameter T (Trait class) to check whether T is a fundamental type or not.
Return Value: This template returns a boolean value as shown below:
- True: if the type is a fundamental.
- False: if the type is a non-fundamental.
Below programs illustrate the is_fundamental template in C++ STL:
Program 1:
// C++ program to illustrate // is_fundamental template #include <iostream> #include <type_traits> using namespace std;
// main program class GFG {
}; int main()
{ cout << boolalpha;
cout << "is_fundamental:"
<< '\n' ;
cout << "GFG :"
<< is_fundamental<GFG>::value
<< '\n' ;
cout << "int :"
<< is_fundamental< int >::value
<< '\n' ;
cout << "int& :"
<< is_fundamental< int &>::value
<< '\n' ;
cout << "int* :"
<< is_fundamental< int *>::value
<< '\n' ;
return 0;
} |
Output:
is_fundamental: GFG :false int :true int& :false int* :false
Program 2:
// C++ program to illustrate // is_fundamental template #include <iostream> #include <type_traits> using namespace std;
// main program int main()
{ cout << boolalpha;
cout << "is_fundamental:"
<< '\n' ;
cout << "float:"
<< is_fundamental< float >::value
<< '\n' ;
cout << "float&:"
<< is_fundamental< float &>::value
<< '\n' ;
cout << "float*:"
<< is_fundamental< float *>::value
<< '\n' ;
cout << "double:"
<< is_fundamental< double >::value
<< '\n' ;
cout << "double&:"
<< is_fundamental< double &>::value
<< '\n' ;
cout << "double*:"
<< is_fundamental< double *>::value
<< '\n' ;
return 0;
} |
Output:
is_fundamental: float:true float&:false float*:false double:true double&:false double*:false
Program 3:
// C++ program to illustrate // is_fundamental template #include <iostream> #include <type_traits> using namespace std;
// main program int main()
{ cout << boolalpha;
cout << "is_fundamental:"
<< '\n' ;
cout << "char:"
<< is_fundamental< char >::value
<< '\n' ;
cout << "char&:"
<< is_fundamental< char &>::value
<< '\n' ;
cout << "char*:"
<< is_fundamental< char *>::value
<< '\n' ;
cout << "void :"
<< is_fundamental< void >::value
<< '\n' ;
return 0;
} |
Output:
is_fundamental: char:true char&:false char*:false void :true